Gas turbine



.Patented Mar. 11, 1941 UNITED STATES PATENT OFFICE GAS TURBINE `Wayne H. Allen, Lynn, Mass., assignor to General Electric Company, a corporation of New York Application December 14, 1939, Serial No. 309,234

4 Claims.

The present invention relates to gas turbines, more particularlyto the type of turbines operated by exhaustgases from a combustion engine as are used on aircraft for driving superchargers or like aircraft auxiliaries. In the usual arrangement of this kind, exhaust gases are directed towards a bucket wheel from a nozzle box located in one side of the wheel. Gases are discharged from the other side of the wheel either directly into the atmosphere, in which case this other side of the wheel is directly disposed to the atmosphere, or the discharge of gas from the wheel into the atmosphere may be accomplished by an exhaust casing surrounding the wheel and having an opening in the Vdirection of the slip stream of the aircraft.

The object of my invention is to provide an improved construction and arrangement of gas turbines of the type aforementioned.

For a consideration of what I consider to be novel and my invention, attention is directed to the following description and the claims appended thereto in connection with the accompanying drawing.

In the drawing, Fig. l illustrates a plan view of a gas turbine arrangement in accordance with my invention, and Fig. 2 is a sectional view along line 2-2 of Fig. 1.

The arrangement comprises a bucket wheel I with a rowof buckets I I secured to an overhung portion of a shaft I2 which is supported on a bearing I3 and may serve for driving a supercharger or the like, not shown. Exhaust gases from a combustion engine or like source, not shown, are conducted to a nozzle box I4 which has a hanged inlet conduit I5 and a row of nozzles IE for properly directing the gases towards the buckets II of the wheel IIJ. The nozzle box is located on one side of the wheel. A device I1 is located on the other side of the wheel for cooling the wheel and preventing gases discharged from the wheel from contacting the central portion thereof. The device Il comprises a cup-shaped disk I8 adjacent the'wheel with an edge I9 in close proximity to the rim of the wheel to form a small clearance therewith in order to prevent flow of gases discharged from the wheel towards the central portion thereof. A conduit 2| is secured to the disk I9 extending diametrically across the disk and forming with the latter a discharge opening 22 for discharging cooling medium towards a short section of the rim of the bucket wheel I0. `Cooling medium in the form of air may be supplied to the conduit 2| from the slip stream of an aircraft. In the present instance I havel indicated an aircraft having an outer wall 23 with openings 2l and 25. Cooling air is conducted to the conduit 2| by a channel 26 projecting through the opening 24 of the wall 23. The cooling and protecting device is supported on the nozzle box by means of brackets 21 and 28. The bracket 2'| is connected to an extension 29 of the device and the bracket 2l is connected to the upper end of the conduit 2|.

The arrangement so far described is more fully l0 disclosed in the copending application of C. W. Smith, Serial No. 281,562, filed on June 28, 1939, and assigned to the same assignee as the present application.

In order to conduct gases discharged from the 15 turbine wheel I9 to the atmosphere, I provide an exhaust casing 30. The exhaust casing according to my invention comprises a ring 9| concentrically surrounding the bucket wheel III and secured to and supported on the nozzle box Il by 2u means of four uniformly spaced lugs 32. These lugs are welded to the ring 3| and are fastened to posts 33 on the nozzle box by bolts 3l. 'I'he left-hand edge of the ring 3| forms a bent 35 which is biased into intimate contact with a packing ring 36 of soft, heat-resistant material located in an annular groove of the nozzle box I4. The right-hand portion of the ring 3| forms a iiange 31. An exhaust conduit or ilight hood 99 is secured to the flange 3l by bolts 39 and projects 30 through the opening 25 in the aircraft wall 23. The conduit 38 opens in the direction of the slip stream indicated by an arrow 4D whereby the discharge of exhaust gases is aided by the slip stream effect. The bolting of the ight hood 39 to the 35 ring 3| and the bolting of the latter to the supercharger by a plurality of bolts permits the night hood always to be installed so that the hot gases are discharged therefrom in rearward direction, that is, in the direction of the slip stream, re- 40 gardless of the location and relationship of any of the other supercharger, openings. The extension or bracket 29 and the conduit 2| of the cooling device project through openings 4| and 42 of V, adjacent portions of the ling 3| and the conduit 45 38. The walls forming the openings 4I and l2 are conically bent outward and rings 43 and M are welded to these conically bent wall portions to form grooves for accommodating and retaining packings 45 and 45 respectively. The rings 50 43 and M and the conically-shaped wall portions form suicient clearances with the adjacent portions of the device I'Ito permit relative expansion between the device and the exhaust casing during operation. Such clearance is also formed Il charged into the atmosphere by the exhaust cas-y ing 30.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Gas turbine arrangement comprising a bucket wheel having a row of buckets, a nozzle box located on one side of the wheel and having a row of nozzles for directing operating gases towards the buckets, a protecting and cooling device located on the other'side of the wheel and having a conduit for conducting cooling air to the wheel, means supporting the device on the nozzle box, and an exhaust casing for-receiving gases discharged irom the wheel enclosing said device and having an opening sealed to the conduit, said casing comprising a ring and a conduit ilanged together and means detachably securing and sealing the ring to the nozzle box.

2. Gas turbine arrangement comprising a bucket wheel, a nozzle box located on one side of the wheel and having a wall forming an annular groove, a protecting and cooling device located on the other side of the wheel and having a conduit for receiving cooling air, and an exhaust casing for receiving gases discharged from the wheel, said casing comprising a ring having an edge projecting into the annular groove, ilexible sealing means in the groove, and means biasing the ring towards the flexible sealing means and supporting the ring on the nozzle box.

3. Gas turbine arrangement comprising a bucket wheel having a row o! buckets, a nozzle box located on one side of the wheel and having a row of nozzles for directing operating gases towards the buckets, a protecting and cooling device located on the other side oi the wheel and having a supply conduit i'or conducting cooling air to the wheel, means supporting the device on the nozzle box, and an exhaust casing for receiving gases discharged from the wheel, said casing comprising a ring and a conduitiianged together, the ring having an edge adjacent the nozzlebox, means including a plurality of lugs supporting the ring on the nozzle box and biasing the ring into sealing contact with the nozzle box, adjacent portions of the iianged ring and exhaust conduit forming an opening through which the supply conduit of the cooling device projects and ilexible packing means to reduce leakage past said opening and to permit relative expansion between the supply conduit and the exhaust casing.

4. Gas turbine arrangement i'or aircraft comprising a bucket wheel, a nozzle box located on one side of the wheel, a cooling device for the wheel located on the other side thereof, an exhaust casing comprising a ring and a conduit for receiving gases discharged from the wheel enclosing said device and having an opening sealed to the conduit, and means including a plurality oi boltssecuring the conduit to the ring and the ring to the nozzle box and permitting adjustment of the conduit to eiiect discharge of gases in direction of the slip stream of an aircraft regardless of the relative locationvot other turbine elements.

WAYNE H. ALLEN. 

